Horizontal crossbar multiswitch control device

ABSTRACT

An improved horizontal crossbar multiswitch utilizes a modified armature assembly comprising several component parts that cooperate when the bar is in a rest position to provide a magnetic field of minimum reluctance in cooperation with an associated electromagnet, and when the bar is in an operating position provide a magnetic field of maximum reluctance by increasing the gap existing between the associated electromagnetic coil and one of the armature component parts. This arrangement prevents the armature from being further energized when the crossbar is in a rotated state by means of reduction in the magnetic forces associated with the high reluctance gap and further provides electrical indication of the operative position of the armature.

United States Patent Maelstai et a1.

HORIZONTAL CROSSBAR MULTISWITCH CONTROL DEVICE Inventors: Serge Marcel Yves Maelstaf,

Bagneux; Jacques Joseph Antoine Altesleben, Saint-Michel-sur-Orge, both of France Assignee: International Standard Electric Corporation, New York, N.Y.

Filed: Aug. 1, 1974 Appl. No.: 493,936

Foreign Application Priority Data Oct. 18, 1973 France 73.37185 References Cited UNITED STATES PATENTS 4/1934 Reynolds 335/112 6/1942 Frederick 335/108 [45] Oct. 21, 1975 2,309,422 1/1943 Vigren et a1. 335/108 2,889,425 6/1959 Yule et al. 335/137 2,961,493 11/1960 Torisu 335/113 Primary Examiner-Harold Broome Attorney, Agent, or Firm-John T. Ol-lalloran; Menotti J. Lombardi, Jr.; Richard A. Menelly [57] ABSTRACT An improved horizontal crossbar multiswitch utilizes a modified armature assembly comprising several component parts that cooperate when the bar is in a rest position to provide a magnetic field of minimum reluctance in cooperation ;with an associated electromagnet, and when the bar is in an operating position provide a magnetic field of maximum reluctance by increasing the gap existing between the associated electromagnetic coil and one of the armature component parts. This arrangement prevents the armature from being further energized when the crossbar is in a rotated state by means of reduction in the magnetic forces associated with the high reluctance gap and further provides electrical indication of the operative position of the armature.

13 Claims, 8 Drawing Figures US. Patent Oct. 21, 1975 Sheet 2 of6 3,914,724

US. Patent Oct. 21, 1975 Sheet 4 of6 3,914,724

US. Patent Oct. 21, 1975 Sheet5of6 3,914,724

Sheet 6 of 6 3,914,724

Patent Oct. 21, 1975 HORIZONTAL CROSSBAR MULTISWllTCI-I CONTROL DEVICE BACKGROUND OF THE INVENTION The present invention concerns improvements to crossbar multiswitches and, more particularly, to the devices which are associated with the horizontal bars of such multiswitches for ensuring their holding, controlling their rotation in either direction and for giving the supervision of the position in which they are.

Crossbar multiswitches are well-known telephone equipments which may be called coordinate selectors since a connection is established at the intersection of two coordinates between an input and an output this intersection physically corresponding to the crosspoint of a horizontal line with a vertical line materialized in the multiswitch by operating bars. That is the reason why these operating bars are called horizontal bars and vertical bars according to the connection field to which they belong.

These vertical and horizontal bars which constitute a multiswitch are mounted in a common steel-plate frame whose shape gives it great rigidity.

Concerning the horizontal bars, it is well-known that their function is to pivot by a small angle in either direction about their longitudinal axis in order to position appropriately, with respect to the vertical bars, the selecting fingers they bear. In order to allow this rotation, the horizontal bars are placed between two screws acting as pivots, the screws being arranged in lugs integral with the frame, that is, with the metallic framework. Moreover, the rotation of the horizontal bar depends upon two electromagnets acting upon a two-wing armature integral with the bar. Besides, in order to check the position in which the horizontal bar lies and to define a rest median position, a lever integral with the armature controls two relay spring pile-ups.

If only the material viewpoint is considered, it can be seen that the horizontal bars need specific equipment, such as electromagnet coils, pile-ups, and'armature levers which cannot be used in any other type of telephone equipment. This results in a specific manufacture particular to horizontal bars.

Moreover, after the equipment of a multiswitch frame, numerous adjustments are necessary in particular as concerns the horizontal bars, in order to determine the position of these bars and their longitudinal play acting upon their pivot screws; to adjust the value of the gaps between each wing of the armature and the pole of the corresponding control coil; to center the bar in rest position in order to obtain equal gaps by deforming, if required, the armature lever. These adjustment cases are not exhaustive and, according to the requirements, other adjustments may be necessary. It can thus be seen that the good operating condition of a horizontal bar necessitates a certain number of adjustments which require a certain amount of time and which can be only carried out by qualified personnel.

SUMMARY OF THE INVENTION The object of the invention is to avoid these drawbacks which concern the problems raised by the manufacture and the adjustment of pieces which can only be used for the horizontal bars. A new, simple and costless control device for the horizontal bars which reduces the adjustments to a minimum, ensures a minimum maintenance and increases the lifetime by reducing the wear of the moving parts is therefore proposed. Moreover, this new device substantially reduces costs since it uses standard pieces such as electromagnetic relays for the control of the bars.

The invention relates to the use of two standard relays for controlling the rotation of each horizontal bar by means of an intermediate piece made of nonmagnetic material and modified relay armatures.

The extremity of each horizontal bar is associated with a plastic intermediate piece which is simultaneously used as support and pivot for the bar. One of these two pieces, or pivots, that controls the bar rotation, includes on each side of the bar rotation axle, a projection and a nipple between which is housed the modified extremity of the armature of one of the two control relays. Each pivot cooperates through its rotation axle with a bearing in plastic material which is fixed on the multiswitch metallic framework. The flanges of each bearing are shaped in order for each to receive one coil of the control relay. This coils acts, in a well-known way, upon an armature, one extremity of which is housed between the projection and the nipple of the pivot controlling the bar rotation; the other extremity acting upon a spring pile-up mounted on the metallic framework-which functions as a frame-yoke. This spring pile-up determines electrical switching which supply indications of the position of bar. An elastic device ensures therestoririg to normal of the horizontal bar and clamps its oscillations.

Moreover, the invention provides that any possible mechanical blocking of a horizontal bar in operating position is always indicated. This indication is due to the presence of nipples adjacent to the projections of the pivot controlling the horizontal bar rotation. Indeed, if the bar remains mechanically blocked when the relay coil ceases to be fed, the armature cannot return to its rest position due to the nipple; it is thus held in operating position which is shown by an appropriate position of the supervision pile-up springs.

In other respects, if under these conditions, the other coil comes to be fed, it is provided that its energization has no effect upon its armature. For this purpose, each armature has two parts so that when the bar is in rest position, the armature offers a magnetic circuit having a minimum reluctance. On the contrary, if a horizontal bar is operated, the projection of the pivot situated on V the opposite side to that which controlled the operation acts upon one of the two parts of the associated armature so that the magnetic circuit presents a maximum reluctance by increasing the gap between thecoil pole and said one part. Under these conditions, if this coil is energized, the resulting magnetic field cannot operate the armature.

It is to be noted concerning the magnetic field and the instant magnetic circuit that the latter has no residual gap between the annature and the yoke whereas an important gap exists in the horizontal bar standard systems of the known type multiswitches. This improvement brought by the invention avoids the magnetic field dispersion.

Various other features will be disclosed from the following description given by way of non-limited examples referring the FIGS. 1 to 8.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, a perspective view of a horizontal bar used in the present invention;

FIG. 2, a perspective view of the horizontal bar and the pivots associated with the extremities of each horizontal bar;

FIG. 3, a perspective view under a different angle of one of the pivots in FIG. 2;

FIG. 4, a perspective view of the bearings supporting the pivots of FIG. 2;

FIG. 5, a perspective view of a bearing equipped with the springs which restore the horizontal bar to normal;

FIG. 6, a schematic plan view showing the restoringto-normal device of the horizontal bar;

FIG. 7, a perspective view of the different elements being the object of the present invention, this view illustrating the way they cooperate after mounting; and

FIG. 8, a perspective view of the different elements constituting the relay armature used in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the horizontal bar proper, that is, the support 1 of selecting fingers 2, without the pivots which are placed at the extremities of this support and allow it to rotate in either direction indicated by the double arrows 3. The U-shaped support 1 is cut in a standard way in order to constitute tongues 4 which may be deformed by means of an appropriate adjusting tool so that as the selecting fingers 2 are respectively fixed on these tongues, they may be adequately positioned.

Besides these features usual to the horizontal bars of the well-known multiswitches, it will be noted that the bar 1 includes two rectangular openings 5 and 6 and two clearances 7 and 8, the length of the opening 5 and of the clearance 7 of one extremity of the bar being greater than that of the opening 6 and of the clearance 8 of the other extremity; the reason why will appear more clearly at the reading of the following description which refers to FIG. 2.

FIG. 2 shows the two ends of the horizontal bar 1 and their respective openings and clearances in order to show the way they cooperate-with the operating pivot 9 and the simple pivot 10.

These pivots are made of injected plastic material which gives them advantages concerning the cost price, the reproduction fidelity, inertia and wear. The plastic material also has self-lubrication properties for avoiding all the problems raised by the rotation axles.

The simple pivot 10 has a thickness ll-which corresponds to the distance 12 between the U branches of a the bar 1 so that it may be easily introduced between said branches. When it is inserted according to the direction indicated by arrow 13, the projection 14 is introduced into the opening 6 until the face 15 of the pivot abuts the internal face of the fU. The simple pivot is then held in its position by means of a non- 4 represented fixing screw which may be self-tapping This screw is screwed in the opening 16 of the pivot through the rectangular opening 6. It will be noted that the latter includes a semi-circular clearance 17. The latter is provided in order that, after fixing of the simple pivot on the horizontal bar, it is possible to insert in the opening 18 the adjusting tool which acts upon the tongue 4 for positioning the selecting finger 2.

The simple pivot also includes a rotation axle 19 and two other clearances which may be better seen on FIG. 3. The rotation axle 19 cooperates with a bearing as will be later described. The clearances 20 and 21 are identical and are used to limit the amplitude of the horizontal bar rotation as it will be later described.

FIG. 2, shows the operating pivot 9 which is more complex than the simple pivot 10 since, although it is used for the fixing of the corresponding horizontal bar extremity, it is also used as an element which controls the bar rotation.

The fixing system is similar to that of the other bar extremity in that it includes a part 22 the thickness of which 23 is slightly smaller than the distance 12 between the branches of the U of bar 1, this part 22 having a projection 24 which includes an opening 25 receiving, e.g., a self-tapping screw. The width of projection 24 is such that it can be inserted with a minimum play into the opening 5, its length being smaller than that of the opening. It will be noted that between the sides of part 22 and walls 26 and 27, there exists a passage; the width of which is slightly greater than the thickness of branches 28 and 29 of the bar 1. Thus, when the latter is fixed on the pivot 9, the branches 28 and 29 are introduced in both passages until the projection 24 is introduced into the opening 5. Before its final positioning via a non-represented screw which is housed in the opening 25, the bar 1 or reciprocally the pivot 9 may be moved in one of the directions indicated by the double arrow 30. This motion is possible since the opening 5 has a length greater than that of projection 24, the clearance 7 being provided so that its shoulder 31 does not abut the pivot 9 when the projection 24 is itself against the edge 32, in either extreme position it may occupy in the opening 5. It is also to be noted that this possible slide of projection 24 in the opening 5 needs between the face 33 of part 22 and the bow 34 a distance at least equal to the thickness of the base 35 of the U of bar 1.

Like the simple pivot 10, the operating pivot 9 has a semi-circular clearance 17 enabling the insertion of the adjusting tool for tongues 4 and a rotation axle 36 which cooperates with a bearing which will be subsequently described. Since the rotation axles 36 and 19 of pivots 9 and 10 are mounted in bearings not yet described but which have a fixed position, and since. the position of the horizontal bar 1 is well determined at one extremity due to the corresponding dimensions of opening 6 and of projection 14, it can be seen that only the positon of pivot 9 with respect to the bar extremity cooperating with this pivot may vary. Indeed, the length of opening 5 is such that projection 24 may 1 move and, in particular, reach the position where it abuts the edge 32. In this position, the rotation axle 36 is completely out of the housing of the fixed bearing provided for receiving it. This facilitates the positioning of the horizontal bar by enabling first the insertion of the rotation axle 19 into its fixed bearing and then the adjustment of the position of pivot 9, that is the position of projection 24 in opening 5, so that the rotation axle 36 is introduced in the housing of the corresponding fixed bearing in order to provide a slight play between the fixed bearing and face 37 of part 22. As bar 1 is integral with pivots 9 and 10 as above-seen by means'of screws which engage openings 16 and 25, this play corresponds to that of the horizontal bar with respect to the bearings which support it in order to enable its correct rotation, that is without friction, around its longitudinal axis terminated by axles 36 and 19. It will be noted that these axles are in the equilibrium axis of the horizontal bar.

The operating pivot 9 includes, moreover, a nipple 38 which enables the holding or restoring after its operation of the horizontal bar to its intermediate rest position as it will be shown later. The function of projections 39 and 40 is to support a relay armature I nose and enable the rotation of the horizontal bar 1 in either direction. The security function of projections 41 and 42 with respect to the horizontal bar operation will be described below.

In a manner similar to the simple pivot where the two clearances and 21 were provided, the pivot 9 also includes two identical clearances 43 and 44 which have the same function as their homologues of pivot 10 and are used to limit the amplitude of the horizontal bar rotation.

FIG. 4 shows two bearings 45 and 46 used as supports for the pivots (9 and 10) in FIG. 2, as well as a part of the metallic framework 47 used as frame-yoke and utilized in particular for fixing bearings such as 45 and 46.

Each bearing includes positioning nipples 48 and 49 onto the frame-yoke 47. When a bearing is positioned, the nipples 48 and 49 engage the corresponding openings 50 and 51, and the minimal play between the nipples and the openings ensure the perpendicularity of the bearing with respect to the frame-yoke, and automatically align the hearings in relation to each other. The fixing of each bearing onto the frame-yoke 47 is carried out by means of a fixing screw e.g. selftapping which is introduced into the blind end bore 52 of the bearing owing to the circular cut 53; this screw non represented in FIG. 4 has its head around the cut 53 on the frame-yoke 47. It will be noted that the bearings 45-46 have a large leaning surface 54 which ensures them a perfect seating on the frame-yoke 47. As above-seen in relation with FIG. 2, the bearings 45 and 46 receive the axles of the horizontal bar simple and operating pivots. These cylindrical axles are housed in a blind end bore of the bearing; such a bore, referenced 55, is represented in dotted line on hearing 46. It can be also seen in FIG. 5.

Bearings 45 and 46 include heels 56 having H-shaped openings 57 which extend through them as indicated by the dotted lines of bearing 46. They also include nipples 58, the function of which is clearly shown in FIG. 5.

In FIG. 5, it can be seen that a bearing 59 has been equipped with springs 60 and 61. These flat springs are identical and include a toothed part 62 which ends by a stop heel 63. The positioning of these springs is very simple since it is sufficient to introduce them by their end 64, each of them in a vertical branch of the 1-1- shaped opening 57 and to move them in the direction of arrow 65 until their heel 63 abuts the inlet of the H opening. In this position, springs 60 and 61 cannot be withdrawn out of the H opening as the teeth of the toothed part 62 bite the plastic material of their housing and prevent any motion in the reverse direction of arrow 65.

Springs 60 and 61 are arranged on either side of the nipple 58 as shown in FIG. 6. In this schematic figure, it can be seen that nipple 58 is narrower on one side than on the other and that it presents accordingly, edges 66 and 67 which diverg progressively. Such an arrangement facilitates the sliding of the extremity 64 of springs 60 and 61 on nipple 58 when they are positioned. The springs each have one single bearing point 68 on nipple 58 and, as the housing area 69 the H- shaped opening determines a distance between the springs 60 and 61 which is smaller than that between the two bearing points 68, it can be seen that, on the one hand, springs 60 and 61 exert a pressure against the nipple 58 at said bearing points and that, on the other hand, their extremities 64 are deflected by a value which corresponds to the housing of nipple 38 of the horizontal bar operating pivot (see also FIG. 2).

Thus, when the horizontal bar is operated, the nipple 38 moves in either direction indicated by the double arrow 70. It therefore acts upon the end 64 of one or the other spring 60 or 61 by moving it away from the corresponding bearing point 68. There results an elastic strain of the spring as long as the bar is operated, that is as long as nipple 38 is not in its rest position. When the horizontal bar is released, the force which has drawn nipple 38 in one of the directions indicated by arrow 70 disappears, so that this nipple is only submitted to the force resulting from the elastic strain of spring 60 or 61 moved away from its bearing point 68. This spring may then return to its position in which it leans against its bearing point 68 and, therefore, by its extremity 64, restore nipple 38 to its initial rest position. Springs 60 and 61 then play a complementary function as regards the damping of the horizontal bar oscillations. Indeed, returning to normal under the action of spring 60 or 61, due to its inertia, the bar and consequently, nipple 38 of the operating pivot, tend to go beyond this rest position and, in short, to oscillate around the intermediate position which is the rest position. This oscillation phenomenon is clamped by the spring which has not been moved by nipple 38. Thus, if the operated bar has driven nipple 38 in the direction in which it acts upon spring 60, when this bar returns to normal, as soon as nipple 38 has reached the intermediate rest position that of FIG. 6 and as soon it goes beyond it in the other direction, nipple 38 acts upon the extremity 64 of the other spring 61 which opposes this motion. The damping of the oscillations of nipple 38 thus of the horizontal bar is in this way quick and efficient since the nipple contacts the extremities of both springs 60 and 61 which each exerts an equal force on nipple 38 in the direction of arrows 71 and 72.

After having examined the arrangements enabling the restoring-to-normal of the horizontal bar, reference to the elements will be described by FIG. 7 which determine its rotation in one direction or the other.

FIG. 4 shows the way bearings 45 and 46 were positioned and then fixed onto the frame-yoke 47 by using the guiding nipples 48 and 49 and a screw which engages the blind-end bore 52. FIG. 7 shows two bearings 73 and 74, the cut-away part of the frame-yoke 47 revealing the nipples 48 and 49 as well as the bore 52 of bearing 73.

This bearing 73 supports the operating pivot 75 which is associated, via the screw 76, with one extremity of the horizontal bar 77. The other extremity of this bar is secured by means of the screw 78 on the simple pivot 79, the latter being supported by the bearing 80, itself mounted on the frame-yoke 81 in the same way as are the bearings 73 and 74 on the frame-yoke 47. In this position, the horizontal bar may operate, the rotation axles 82 and 83 represented in dotted lines of the pivots 75 and 79 engaging the related housings provided in bearings 73 and 80 (blind-end bores 55 in FIGS. 4 and 5).

The operation of this horizontal bar is under control of two standard electromagnetic relays as it will be now seen. It will be noted that these relays are not identically represented. In order to facilitate the understanding of the description, one of the relays has been represented with only its coil 101 and a check 103. Concerning the other relay, the homologous coil and cheek are hidden since the armature 85-8990 is positioned as well as the pile-up 96 operated by the latter. Nevertheless, it is obvious that both relays are strictly identical in the existing equipment. During the description of the operating pivot in relation with FIG. 2, it has been seen that pivot 9 (pivot 75 in FIG. 7) includes two projections 39 and 40 and two nipples 41 and 42. Between each projection and its corresponding nipple, the armature of one of the two control relays is introduced. In FIG. 7, projection 40, nipple 42 and nipple 41 can be seen, however, projection 39, corresponding to the latter, cannot be seen since between it and nipple 41 the operating nose 84 of the armature is engaged. This armature the operation of which will be detailed further on includes besides the nose 84, a plate 85 controlling a lever 86, a retainer 87 including a fixing lug 88, a counter-plate 89 and a joint spring 90. This armature is then held, in a well-known way, in contact with the edge 91 of the yoke constituted by the frame-yoke 47 by means of the retainer 87; the lug 88 of the latter is fixed onto the frame-yoke 47 by means of the screw 92 which engages a threaded opening such as 93, the positioning being facilitated by the guiding nipple 94. The armature lever 86 also acts, in a well-known way, when the armature is operated, upon the mobile guide 95 of a spring pile-up 96, the guide 97 being fixed and leaning against part 127 of the plate 128. In this way, the contacted parts of springs 98 integral with the mobile guide 95 may contact the contacted parts of springs 99 integral with the fixed guide 97. It willbe noted that the pile-up 96 is fixed on the plate 128 by means of screws 100 and that plate 128 itself is rendered integral with the frame-yoke 47 by means of a screw which is introduced from the hidden face of this frame-yoke.

The above-described armature is controlled by a relay coil. However, this coil cannot be seen in FIG. 7 since it is placed between the bearings 73 and 74 and is hidden by the armature itself. In order to make clear the description concerning this relay coil, a part of the frame-yoke 47 has been cut-away and the armature, whose operating nose such as nose 84 normally fits between the projection 40 and the nipple 42 of the operating pivot 75 has been removed. Coil 101 controls an armature exactly identical to the one just described, said armature acting upon a spring pile-up the same as pile-up 96 and near the latter.

The mounting way of the coil has not been represented, the latter being fixed on a square fold of the frame-yoke 47 by means of a screw which is housed in the core 102 itself, in the core extremity opposed to the one visible in the figure. In this position, coil 101 and the other coils are housed between two bearings such as 73. For this purpose, the distance between two adjacent bearings is slightly greater than the width of cheek 103 of the coil and rounded clearances 104 have been provided on the bearings for housing oval coils such as coil 101.

It will be noted that the length of cheek 103 is greater than that of bearing 73 so that the homologous edge to edge 105 faces one of the two clearances 106 provided on the operating pivot (clearances 43 and 44 of pivot 9 in FIG. 2). This arrangement mechanically limits the rotation of the horizontal bar 77 in either direction. Indeed, assuming that the motion exerted by nose 84 upon the hidden projection homologous to projection 40 of pivot 75 is exaggerated, the rotation of bar 77 about its rotation axle 82 would anyway be limited since the edge of clearance 106 would abut the edge 107 of cheek 103.

It is to be noted that the function of clearance 108 of the simple bearing 79 an identical clearance being provided on the hidden part of said bearing (see clearances 20 and 21 in FIG. 3) is identical and also limits the rotation of bearing 79 and of the bar 77 by abutting the cheek edge of the coil non-represented in FIG. 7 but which is housed, as it has been seen for coil 101, in the rounded clearance 104 of bearing 80.

The function of nipples 41 and 42 mentioned with the description of FIG. 2 will now be described. For this purpose, it is to be assumed that the horizontal bar 77 has been operated by the nose 84 after the counterplate 89 has been energized by its relay coil and that, for any reason, when the coil ceases to be energized, although its counter-plate ceases to be attracted towards the coil, the horizontal bar does not return to normal. If nipple 41 did not exist, the horizontalbar could remain blocked in its operating position and nevertheless the counter-plate 89 could return to its rest position. Now the restoring-to-normal of the counterplate 89 also corresponds to the restoring of the armature lever 86 and, consequently to that of the springs of pile-up 96. As it is the operating position of the armature which indicates that the horizontal bar is actuated due to the establishment of the spring contacts of pile-up 96, it can be seen that it is necessary to hold the armature in an operating position when the latter ceases to be energized by its coil. When the horizontal bar remains mechanically blocked despite the return force exerted by the springs of the pile-up upon the armature lever 86, and the return force of spring restoring-to-normal the armature of the other coil 101, the holding of the armature in an operating position is the function of nipples 41 and 42. The nose 84, being engaged between the operating projection 39 (visible in FIG. 2) and nipple 41, as long as the bar 77 has not returned to the rest position of the figure, nipple 41 holds nose 84 and the entire armature in an operating position, which is indicated by the closure of the make contacts and the opening of the break contacts of the springs of pile-up 96. This switching function indicates to the appropriate circuits the position in which the bar is. t

The control of each horizontal bar necessitates two relays and one pivot 75, each-armature cooperating with a projection and nipple set such as'40 and 42 for operating the bar in one or the other direction. This control is necessary only upon one or the other bar extremity but not upon both at the same time. Thus, when oneextremity of a horizontal bar is equipped with the operatingpivot 75, its other extremity is associated with a simple pivot 79 which solely ensures the fixing of the horizontal bar and the rotation about its rotation axle 83. This arrangement makes it possible to save space by mounting the operating pivots 75 on a given extremity ofa horizontal bar then on the other extremity of the adjacent horizontal bar and so on. It results that, on a same row of bearings, only one bearing out of two cooperates with an operating pivot. It is the case of bearing 73 which is associated with the operating pivot 75 whereas the adjacent bearing 74 is associated with the simple pivot 109.

That is why on a same row of bearings, only one bearing out of two is equipped with springs 60 and 61 as represented in FIG. 5. Bearing 73 of FIG. 7 includes such springs 60 and 61 as it cooperates with the operating pivot 75 and that the latter is provided with nipple 38 (see also FIGS. 2 and 6) which restores the horizontal bar to normal and clamps its oscillations. On the contrary, the adjacent bearing 74 has no springs 60 and 61 as it is associated with a simple pivot 109. Each horizontal bar such as 77 is thus associated, via one of its extremities, with an operating pivot 75 and a bearing 73 equipped with springs 60 and 61 and, byits other extremity, with a simple pivot 79 and a bearing 80 not equipped with springs. Such an arrangement in not limiting and, for standardization reasons, it may be contemplated that both bearings be equipped with springs, one of the two sets of springs playing no part in the operation.

It has been noted during the above description that the armature comprises several parts, in particular a plate 85, a counter-plate 89 and a joint spring 90. This relative complexity of the armature is explained by the fact that in case of the horizontal bar blocking in one rotation direction, it is necessary to prevent the armature acting in the other rotation direction from operating when the relay coil controlling this armature is energized.

As shown on FIG. 8, the plate 85 includes an opening 110 which enables the introduction of the coil core (referenced 102 in FIG. 7). Around one part of this opening, a stamping 111 has been provided which houses the counter-plate 89, the dimension 112 of the stamping corresponding to the width 113 of the counter-plate. The rounded end 114, provided for covering the coil pole, is thus placed between the edges of the deflected part 115 of the plate. The joint spring 90 includes four circular openings. Openings 116 and 117 cooperate with nipples 118 and 119 for crimping spring 90 onto the counter-plate 89 whereas openings 120 and 121 and nipples 122 and 123 ensure the crimping of spring 90 on plate 85. The rectangular opening 124 provided in spring 90 gives to the latter greater flexibility.

Such a constitution of the armature enables that when the control coils of a horizontal bar are not energized and the bar is at rest, noses 84 (FIGS. 8 and 7) of the armatures of both coils being normally between their projection and nipple such as 40 and 42 (FIG. 7) the magnetic circuit offered to the pole of the coil core is constituted by the plate part near the opening 110 as well as by the counter-plate 89. The gap is then minimal between the rounded end 114 and the core pole since spring 90 tends to apply the counter-plate 89 to the bottom of stamping 111.

On the contrary, if the horizontal bar is in one of its two operating positions, according to this position, ei-

ther nipple 41, or nipple 42 (FIG. 7) holds the nose 84 ofits corresponding counter-plate and, thus, the associated armature in operating position. It will be assumed, according to the representation of FIG. 7, that it is the nipple 41 which holds the nose 84 of the counter-plate 89 in such an operating position. The nose 84, under the action, in particular, of the return force of pile-up 96, exerts a force in the direction of arrow 125 (FIG. 8) on nipple 41 due to the horizontal bar blocking. As aboveseen, the plate is then in operating position and its lever 86 holds the springs of pile-up 96 in operating position (FIG. 7) thus determining the appropriate electrical switchings.

Projection 40 (FIG. 7) is no longer in the rest position of the figure and has moved in the direction of arrow 126 (FIG. 7). It has thus exerted a force in the direction of arrow (FIG. 8) upon the nose 84 of the counter-plate with which it cooperates. Opposing the action of spring 90, the counter-plate 89 thus moves away from stamping 111 and, in particular, the rounded part 114, of the coil pole. Thus, if this coil is energized at this time, the gap and the magnetic field dispersion prevent the attracting the counter-plate 89 and, consequently, the plate 85. The horizontal bar then remains in its blocking position which makes it possible to indicate this abnormal situation to the appropriate personnel-attendance for repair.

Although it is not shown in FIG. 7, in particular, it is to be noted that the arrangement of the horizontal bar operating projections and plates is such that the rotation angle of this horizontal bar is greater than the angle corresponding to the necessary motion of the selecting fingers 2 for the latter cooperating with the selector operating guide which is not represented in the figure. This means that the run of the relay armature is greatly sufficient'to determine such rotation angles, which avoids the adjustment of the selecting finger run, without increasing thegap between the armature and the coil which would entail an increase of the number of ampere-turns necessary to the relay thus of its consumption for driving its armature.

Moreover, it will be noted that in the improvements disclosed in the present invention, contrary to the standard multiswitches in which the horizontal bar itself controls the switching spring pile-ups, the horizontal bar is herewith controlled and thus plays no part in the operation of the spring pile-ups. Indeed, it has been seen that both functions are totally separated and that it is the relay or more exactly its armature which ensures, on the one hand, the control of the horizontal bar rotation and, on the other hand, the operation of the switching spring pile-up which shows the horizontal bar position.

Under these conditions, the horizontal bar only rotates about its longitudinal axis without having to exert, as it is the case in standard multiswitches, transverse forces for operating the switching spring pile-ups. As these forces react upon the pivots they cause their wear so that the fact of avoiding such forces substantially reduces the pivot wear.

It is clear that the preceding description has only been given by way of example only and that numerous alternatives may be considered without departing from the scope of the invention.

We claim:

1. An improved crossbar multiswitch of the type having a horizontal bar rotatably controlled by two electromagnets and two corresponding armatures so that the position of the bar is determined by the action of mechanically controlled switching elements wherein the improvement comprises:

a pair of first and second armature plates movably connected to each of said first and second armatures by means of spring members, said plates positioned proximate each of said armatures and said electromagnets for varying the magnetic gap reluctance therebetween said armatures and said electromagnets; and a pair of bearing members intermediate said bar and a fixed housing for rotatably supporting said bar. 2. The improved crossbar multiswitch of claim 1 furif ther including a pair of projection members fixedly attached to each of said bearing members for contacting a part of said first armature plate and to hold said first armature plate proximate said first electromagnet to provide a gap of low magnetic reluctance between said first armature and a first electromagnet when said bar is in a first operation position, and for releasing a part of said second plate to allow said second plate to move away from a second electromagnet to provide a gap of high magnetic reluctance therebetween said second armature and said second electromagnet.

3. The improved crossbar multiswitch according to claim 1 wherein said electromagnetic elements comprise two relays, and wherein each said armature plate includes an extension for cooperating with one of the projections on said bearing members.

4. The improved crossbar multiswitch according to claim 3 wherein the armature plate mechanically cooperates with one of the projections of the bearing member associated therewith, and each armature cooperates with a plurality of said switching elements associated with each bar so that the state of said switching elements indicates the position of operation of each said associated bar.

5. An improved crossbar multiswitch according to claim 1 wherein each horizontal bar is associated with two bearing members one at each end of said bar, each of said bearing members providing pivot and support means to both ends of said bar, and wherein each said bearing members cooperates with a mounting piece for providing bearing means for a rotation axle engaging an associated opening in said mounting piece.

6. An improved crossbar multiswitch according to claim 5 wherein at least one of the two bearing members includesHmeans for positioning the bar in its rest position and wherein the mounting piece cooperating with the bearing member further includes means for positioning said bearing member to a rest position and means for damping oscillations of the bar about its rest position.

7. The improved crossbar multiswitch according to claim 1 wherein each bearing member. associated with a particular horizontal bar includes a parallelepipedic projection cooperating with a rectangular opening in the bar for providing centering and positioning to the bar and wherein the projection is fixedly attached on each bearing memberby means of a screw.

8. An improved crossbar multiswitch according to claim 5 wherein each of the mounting pieces cooperates with a particular bar and includes a first blind end bore on a first face of said mounting piece for providing bearing means for a rotation axle of the bearing member with which said mounting piece is associated, and

nipples, and wherein each said mounting piece further includes a second blind end bore for providing attachment means between each mounting piece and the framework, each said mounting piece further providing a pair of lateral flanks each of said flanks identically shaped for receiving a relay coil and for providing passage for one cheek of each said coil.

9. An improved crossbar multiswitch according to claim 8 wherein each of said relay coils associated with a particular mounting piece controls a double-ended armature, one end of said armature contacts a projection for causing said bearing member to rotate in a first predetermined direction, the other of said armatures cooperating with a pile-up of springs, said springs being electrically connected to switching circuits, so that attenuation of one coil operatively displaces an armature in cooperation with said coil and the displacement of said armature caused one end of said armature to contact a projection on a corresponding bearing member, said bearing member thereby brought into rotation about its rotation axle causing said horizontal bar to rotate in communication therewith, and whereby the other end of said armature operatively engages said pile-up of springs for providing an electrical indication relating to the position of said bar.

10. An improved crossbar multiswitch according to claim 6 wherein said means for providing a rest position for the horizontal bar comprises a nipple parallelly adjacent to the longitudinal axis of the bar and attached to the bearing member controlling the rotation of the bar and a pair of first and second springs one end of each spring being fixedly attached to the mounting piece associated with the bearing member, said means further comprising a projection on said mounting piece and intermediate said pair of springs for providing a bearing point for each spring and for providing separation means between free ends of said pair of springs whereby this projection further provides a separation distance for determining elastic deformation of said free ends when said free ends communicate with the nipple of said bearing member, whereby the rotation of the bar causes the displacement of said nipple and said nipple correspondingly contacts the free end of the first of said springs forcing said spring away from said bearing point thereby increasing the elastic deformation of said spring so that when the bar ceases to rotate said first spring elastically operates upon said nipple for damping said horizontal bar when said bar ceases to rotate returning said bar to its rest state said second spring also providing elastic damping to the displace- 'ments of said nipple while said nipple oscillates about its position of rest.

11. An improved crossbar multiswitch according to claim 9 wherein each said bearing member further includesa pair of clearance members symmetrically arranged along the longitudinal axis of the bar proximately adjacent to the associated mounting piece, each of said clearance members facing a cheek extremity of one of the rotation control coils of the bar whereby the amplitude of the rotation of said bearing member is de termined by the clearance between said bearing member and said coil cheek.

12. An improved crossbar multiswitch according to claim 3 wherein each said bearing member further includes a nipple intermediately adajacent said end of the armature and said projection with which the armature end is operatively associated so that said nipple provides blocking means to said armature end in an operating position and said nipple in contact with said armature end thereby prevents said armature from returning to its rest position when the coil associated with said armature is de-energized and the horizontal bar is mechanically blocked.

13. The improved crossbar multiswitch according to claim 3 wherein the armature comprises a plate, a

counter-plate, and a joint spring and wherein said plate second spring being fixedly attached to both the plate and counter-plate for moving said counter-plate into said recess so that the gap resulting between said pole and said other end of said counter-plate is minimal thereby causing magnetic reluctance therebetween to be a maximum value, and wherein the counter-plate is moved so that the other end of said counter-plate is moved up from said recess when the one said end of the counter-plate which actuates rotation is acted upon in opposition to a force exerted on said counter-plate by the joint spring whereby the gap between said pole and counter-plate is maximal and the resulting magnetic force is reduced so that the magnetic force existing between said pole and counter-plate thereby has no effect on the counter-plate so that when the horizontal bar is mechanically blocked in an operating position the resulting displacement of the bearing member that causes the rotation in the opposite operating position thereby opposingly forces the joint spring to act upon the associated counter-plate so that energization of the coil associated with the armature has no displacement effect 

1. Aen improved crossbar multiswitch of the type having a horizontal bar rotatably controlled by two electromagnets and two corresponding armatures so that the position of the bar is determined by the action of mechanically controlled switching elements wherein the improvement comprises: a pair of first and second armature plates movably connected to each of said first and second armatures by means of spring members, said plates positioned proximate each of said armatures and said electromagnets for varying the magnetic gap reluctance therebetween said armatures and said electromagnets; and a pair of bearing members intermediate said bar and a fixed housing for rotatably supporting said bar.
 2. The improved crossbar multiswitch of claim 1 further including a pair of projection members fixedly attached to each of said bearing members for contacting a part of said first armature plate and to hold said first armature plate proximate said first electromagnet to provide a gap of low magnetic reluctance between said first armature and a first electromagnet when said bar is in a first operation position, and for releasing a part of said second plate to allow said second plate to move away from a second electromagnet to provide a gap of high magnetic reluctance therebetween said second armature and said second electromagnet.
 3. The improved crossbar multiswitch according to claim 1 wherein said electromagnetic elements comprise two relays, and wherein each said armature plate includes an extension for cooperating with one of the projections on said bearing members.
 4. The improved crossbar multiswitch according to claim 3 wherein the armature plate mechanically cooperates with one of the projections of the bearing member associated therewith, and each armature cooperates with a plurality of said switching elements associated with each bar so that the state of said switching elements indicates the position of operation of each said associated bar.
 5. An improved crossbar multiswitch according to claim 1 wherein each horizontal bar is associated with two bearing members one at each end of said bar, each of said bearing members providing pivot and support means to both ends of said bar, and wherein each said bearing members cooperates with a mounting piece for providing bearing means for a rotation axle engaging an associated opening in said mounting piece.
 6. An improved crossbar multiswitch according to claim 5 wherein at least one of the two bearing members includes means for positioning the bar in its rest position and wherein the mounting piece cooperating with the bearing member further includes means for positioning said bearing member to a rest position and means for damping oscillations of the bar about its rest position.
 7. The improved crossbar multiswitch according to claim 1 wherein each bearing member associated with a particular horizontal bar includes a parallelepipedic projection cooperating with a rectangular opening in the bar for providing centering and positioning to the bar and wherein the projection is fixedly attached on each bearing member by means of a screw.
 8. An improved crossbar multiswitch according to claim 5 wherein each of the mounting pieces cooperates with a particular bar and includes a first blind end bore on a first face of said mounting piece for providing bearing means for a rotation axle of the bearing member with which said mounting piece is associated, and wherein each of said mounting pieces further includes a first nipple on a second face said first nipple used as a bearing point for an elastic restoring and oscillating damping element on the bar and wherein each said mounting pieces further includes a set of second nipples on a third face oppositely adjacent to said first face, said second nipples providing means for positioning the mounting piece on a multiswitch framework in cooperation with associated openings for said second nipples, and wherein each said mounting piece further includes a second blind end borE for providing attachment means between each mounting piece and the framework, each said mounting piece further providing a pair of lateral flanks each of said flanks identically shaped for receiving a relay coil and for providing passage for one cheek of each said coil.
 9. An improved crossbar multiswitch according to claim 8 wherein each of said relay coils associated with a particular mounting piece controls a double-ended armature, one end of said armature contacts a projection for causing said bearing member to rotate in a first predetermined direction, the other of said armatures cooperating with a pile-up of springs, said springs being electrically connected to switching circuits, so that attenuation of one coil operatively displaces an armature in cooperation with said coil and the displacement of said armature caused one end of said armature to contact a projection on a corresponding bearing member, said bearing member thereby brought into rotation about its rotation axle causing said horizontal bar to rotate in communication therewith, and whereby the other end of said armature operatively engages said pile-up of springs for providing an electrical indication relating to the position of said bar.
 10. An improved crossbar multiswitch according to claim 6 wherein said means for providing a rest position for the horizontal bar comprises a nipple parallelly adjacent to the longitudinal axis of the bar and attached to the bearing member controlling the rotation of the bar and a pair of first and second springs one end of each spring being fixedly attached to the mounting piece associated with the bearing member, said means further comprising a projection on said mounting piece and intermediate said pair of springs for providing a bearing point for each spring and for providing separation means between free ends of said pair of springs whereby this projection further provides a separation distance for determining elastic deformation of said free ends when said free ends communicate with the nipple of said bearing member, whereby the rotation of the bar causes the displacement of said nipple and said nipple correspondingly contacts the free end of the first of said springs forcing said spring away from said bearing point thereby increasing the elastic deformation of said spring so that when the bar ceases to rotate said first spring elastically operates upon said nipple for damping said horizontal bar when said bar ceases to rotate returning said bar to its rest state said second spring also providing elastic damping to the displacements of said nipple while said nipple oscillates about its position of rest.
 11. An improved crossbar multiswitch according to claim 9 wherein each said bearing member further includes a pair of clearance members symmetrically arranged along the longitudinal axis of the bar proximately adjacent to the associated mounting piece, each of said clearance members facing a cheek extremity of one of the rotation control coils of the bar whereby the amplitude of the rotation of said bearing member is determined by the clearance between said bearing member and said coil cheek.
 12. An improved crossbar multiswitch according to claim 3 wherein each said bearing member further includes a nipple intermediately adajacent said end of the armature and said projection with which the armature end is operatively associated so that said nipple provides blocking means to said armature end in an operating position and said nipple in contact with said armature end thereby prevents said armature from returning to its rest position when the coil associated with said armature is de-energized and the horizontal bar is mechanically blocked.
 13. The improved crossbar multiswitch according to claim 3 wherein the armature comprises a plate, a counter-plate, and a joint spring and wherein said plate further includes a recess for housing the counter-plate one end of the counter-plate operatively cooperating with the projection that causes the rotation of the bEaring member in one direction, the other end of said counter-plate is associated with a coil core pole; the second spring being fixedly attached to both the plate and counter-plate for moving said counter-plate into said recess so that the gap resulting between said pole and said other end of said counter-plate is minimal thereby causing magnetic reluctance therebetween to be a maximum value, and wherein the counter-plate is moved so that the other end of said counter-plate is moved up from said recess when the one said end of the counter-plate which actuates rotation is acted upon in opposition to a force exerted on said counter-plate by the joint spring whereby the gap between said pole and counter-plate is maximal and the resulting magnetic force is reduced so that the magnetic force existing between said pole and counter-plate thereby has no effect on the counter-plate so that when the horizontal bar is mechanically blocked in an operating position the resulting displacement of the bearing member that causes the rotation in the opposite operating position thereby opposingly forces the joint spring to act upon the associated counter-plate so that energization of the coil associated with the armature has no displacement effect thereupon. 